Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34E13C433F5 for ; Fri, 19 Nov 2021 09:26:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B2F161AEC for ; Fri, 19 Nov 2021 09:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234292AbhKSJ3E (ORCPT ); Fri, 19 Nov 2021 04:29:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232838AbhKSJ3D (ORCPT ); Fri, 19 Nov 2021 04:29:03 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9EB94C061574 for ; Fri, 19 Nov 2021 01:26:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=V6V5lGfCPOd68nz+VKS5XbKmgxvfftjeznJyuXXVPps=; b=NMYnunh6Dqrg8Ie5ghxSl/Tequ P2P1j4gmBXB/fhcmrjdIVkkFkgk96WwAmvDcH3GX4pf8z1/46vLV2GyaGEek6DFx0X8faYQFJnqiu VkNrVeWZnigxs7RZ/3pQVM2GeSlF2FiwVU/FLYhJx6hfDU0ZEiGOqM5ZjrrtWM2LFSBZpl4TM4133 KApt9Kh/Mw3IW3rbxHChRsfKHclXqv2t+CIp5PETRh+EE9CqLGztwaTTKl9Du8oNqZ6L6Ggd6yk7b ixP0v6ysqWtkO5Kp2vpF72WOFM1zuijYDkPnrHrr0Vi70mH1DQNw7V4JJVtmLvwsc7VLSEmZU6xv4 JMj+by/g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mo08p-00GrnM-Ie; Fri, 19 Nov 2021 09:25:10 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2A13E300129; Fri, 19 Nov 2021 10:25:05 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D7104265BA04B; Fri, 19 Nov 2021 10:25:05 +0100 (CET) Date: Fri, 19 Nov 2021 10:25:05 +0100 From: Peter Zijlstra To: Peng Wang Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Add busy loop polling for idle SMT Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 19, 2021 at 11:19:03AM +0800, Peng Wang wrote: > > Yes, idle SMT busy loop polling can only provide approximately pipeline > interference for normal instructions. > > When it comes to AVX works, we notice an idea modifing CPU time > accounting[1], do you think the combination can lead to a feasible > solution, or any other better ideas? I'm not at all interested in solving this business model induced brain trauma.